Date

A Search for jet handedness in hadronic Z0 decays

The SLD collaboration Abe, K. ; Abt, I. ; Ahn, C.J. ; et al.
Phys.Rev.Lett. 74 (1995) 1512-1516, 1995.
Inspire Record 378343 DOI 10.17182/hepdata.19666

We have searched for signatures of polarization in hadronic jets from $Z~0 \rightarrow q \bar{q}$ decays using the ``jet handedness'' method. The polar angle asymmetry induced by the high SLC electron-beam polarization was used to separate quark jets from antiquark jets, expected to be left- and right-polarized, respectively. We find no evidence for jet handedness in our global sample or in a sample of light quark jets and we set upper limits at the 95\% C.L. of 0.063 and 0.099 respectively on the magnitude of the analyzing power of the method proposed by Efremov {\it et al.}

1 data table

Polarized E- beam. Events were classified as being of light or heavy flavors based on impact parameters of charged tracks measured in the vertex detector. Jet handedness are measured for helicity-based and chirality-based analysis (seetext). C=95PCT CL indicates the upper limits at the 95 PCT C.L. on the magnitudes.


Measurement of W - photon couplings with CDF in p - anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, M.G. ; Amidei, D. ; et al.
Phys.Rev.Lett. 74 (1995) 1936-1940, 1995.
Inspire Record 377331 DOI 10.17182/hepdata.42429

We report on a study of W+ photon production in approximately 20 pb−1 of p−p¯ collisions at s=1.8 TeV recorded with the Collider Detector at Fermilab. Our results are in good agreement with standard model expectations and are used to obtain limits on anomalous CP-conserving WWγ couplings of −2.3<Δκ<2.2 for λ=0 and −0.7<λ<0.7 for Δκ=0 at 95% C.L. We obtain the same limits for CP-violating couplings. These results provide limits on the higher-order electromagnetic moments of the W boson of 0.8

1 data table

E + MU combined. Limits on CP-conserving anomalous WWGAMMA couplings DELTA(K) and LAMBDA (see paper).


Photoproduction of J / psi mesons at HERA

The H1 collaboration Ahmed, T. ; Aid, S. ; Andreev, V. ; et al.
Phys.Lett.B 338 (1994) 507-518, 1994.
Inspire Record 376566 DOI 10.17182/hepdata.45103

We present a study of J ψ meson production in collisions of 26.7 GeV electrons with 820 GeV protons, performed with the H1-detector at the HERA collider at DESY. The J ψ mesons are detected via their leptonic decays both to electrons and muons. Requiring exactly two particles in the detector, a cross section of σ(ep → J ψ X) = (8.8±2.0±2.2) nb is determined for 30 GeV ≤ W γp ≤ 180 GeV and Q 2 ≲ 4 GeV 2 . Using the flux of quasi-real photons with Q 2 ≲ 4 GeV 2 , a total production cross section of σ ( γp → J / ψX ) = (56±13±14) nb is derived at an average W γp =90 GeV. The distribution of the squared momentum transfer t from the proton to the J ψ can be fitted using an exponential exp(− b ∥ t ∥) below a ∥ t ∥ of 0.75 GeV 2 yielding a slope parameter of b = (4.7±1.9) GeV −2 .

4 data tables

No description provided.

No description provided.

QED background subtracted.

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Measurement of nuclear transparencies from exclusive rho0 meson production in muon - nucleus scattering at 470-GeV

The E665 collaboration Adams, M.R. ; Aid, S. ; Anthony, P.L. ; et al.
Phys.Rev.Lett. 74 (1995) 1525-1529, 1995.
Inspire Record 379818 DOI 10.17182/hepdata.42484

Nuclear transparencies measured in exclusive incoherent ρ0 meson production from hydrogen, deuterium, carbon, calcium, and lead in muon-nucleus scattering are reported. The data were obtained with the E665 spectrometer using the Fermilab Tevatron muon beam with a mean beam energy of 470 GeV. Increases in the nuclear transparencies are observed as the virtuality of the photon increases, in qualitative agreement with the expectations of color transparency.

1 data table

No description provided.


Measurement of the proton structure function F2 from the 1993 HERA data

The ZEUS collaboration Derrick, M. ; Krakauer, D. ; Magill, S. ; et al.
Z.Phys.C 65 (1995) 379-398, 1995.
Inspire Record 375999 DOI 10.17182/hepdata.45104

The ZEUS detector has been used to measure the proton structure functionF2. During 1993 HERA collided 26.7 GeV electrons on 820 GeV protons. The data sample corresponds to an integrated luminosity of 0.54 pb−1, representing a twenty fold increase in statistics compared to that of 1992. Results are presented for 7

13 data tables

No description provided.

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Production characteristics of K0 and light meson resonances in hadronic decays of the Z0

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Z.Phys.C 65 (1995) 587-602, 1995.
Inspire Record 377487 DOI 10.17182/hepdata.48348

An analysis of inclusive production of K0 and the meson resonances K*±(892), ρ0(770),f0(975) andf2(1270) in hadronic decays of the Z0 is presented, based on about 973,000 multihadronic events collected by the DELPHI detector at LEP during 1991 and 1992. Overall multiplicities have been determined as 1.962±0.060 K0 mesons, 0.712±0.067 K*±(892) and 1.21±0.15ρ0(770) per hadronic Z0 decay. The average multiplicities off0(975) for scaled momentum,xp, in the range 0.05≤xp≤0.6 and off2(1270) for 0.05≤xp≤1.0 are 0.098±0.016 and 0.170±0.043 respectively. Thef0(975) and ρ0(770)xp-spectra have similar shapes. Thef2(1270)/ρ0(770) ratio increases withxp. The average multiplicities and the differential cross sections are compared with the JETSET Parton Shower model. The model with default parameters fails to reproduce the experimental K0 momentum spectrum at low momentum, describes the K*±(892) and ρ0(770)xp-spectrum shapes, but significantly overestimates their production rates.

13 data tables

Average multiplicity per hadronic event. Extrapolation to the full X range using the X-shape predicted by JETSET 7.4 PS model.

Average multiplicity per hadronic event. Extrapolation to the full X range using the X-shape predicted by JETSET 7.4 PS model.

Average multiplicity per hadronic event. Extrapolation to the full X range using the X-shape predicted by JETSET 7.4 PS model.

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Single spin asymmetries and invariant cross-sections of the high transverse momentum inclusive pi0 production in 200-GeV/c p p and anti-p p interactions

The FNAL E704 collaboration Adams, D.L. ; Akchurin, N. ; Belikov, N.I. ; et al.
Phys.Rev.D 53 (1996) 4747-4755, 1996.
Inspire Record 382392 DOI 10.17182/hepdata.40544

The π0 inclusive and semi-inclusive, single-spin asymmetries have been measured using transversely polarized, 200-GeV/c proton and antiproton beams colliding with an unpolarized hydrogen target. The measured asymmetries are consistent with zero within the experimental uncertainties for the kinematic region -0.15

3 data tables

No description provided.

Pure inclusive reaction.

Semi-inclusive reaction where at least on associated charged particle is produced at (180+-30) degrees relative to the pi0.


Transverse momentum compensation in pi+ p interactions at 250-GeV/c

The EHS/NA22 collaboration Agababyan, N.M. ; Ajinenko, I.V. ; Białkowska, H. ; et al.
Z.Phys.C 64 (1994) 381-390, 1994.
Inspire Record 376919 DOI 10.17182/hepdata.41987

Compensation of transverse momentum is studied in π+p interactions at 250 GeV/c. SignificantpT-transfer is found between c.m.s. hemispheres. With respect to the beam axis transverse momentum is compensated over the whole event, with respect to the sphericity axis mainly within one hemisphere. The highestpT in the event is mainly compensated by increased multiplicity. The QGSM and FRITIOF models qualitatively reproduce these effects, but important differences are observed.

3 data tables

Mean value of total transverse VECTOR defined as sum over all charged particles in the forward or backward hemispheres was measured.

Mean value of total transverse VECTOR defined as sum over all charged particles in the forward or backward hemispheres was measured.

No description provided.


A Precision measurement of the prompt photon cross-section in p anti-p collisions at S**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, M.G. ; Amidei, D. ; et al.
Phys.Rev.Lett. 73 (1994) 2662-2666, 1994.
Inspire Record 375582 DOI 10.17182/hepdata.19680

A prompt photon cross section measurement from the Collider Detector at Fermilab experiment is presented. Detector and trigger upgrades, as well as 6 times the integrated luminosity compared with our previous publication, have contributed to a much more precise measurement and extended PT range. As before, QCD calculations agree qualitatively with the measured cross section, but the data has a steeper slope than the calculations.

1 data table

Note that the sytematic uncertainties are approximately 100 pct correlated bin to bin.


Spin asymmetry in muon - proton deep inelastic scattering on a transversely polarized target

The Spin Muon (SMC) collaboration Adams, D. ; Adeva, B. ; Arik, E. ; et al.
Phys.Lett.B 336 (1994) 125-130, 1994.
Inspire Record 375478 DOI 10.17182/hepdata.48344

We measured the spin asymmetry in the scattering of 100 GeV longitudinally-polarized muons on transversely polarized protons. The asymmetry was found to be compatible with zero in the kinematic range $0.006

2 data tables

No description provided.

Nucleon spin structure function g2.